JP2004195486A - Emergent retreating method for feeder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reliably prevent interference of a feeder with a press when an abnormality occurs in a drive system of the feeder. <P>SOLUTION: When an abnormality occurs in other drive systems except at least one drive system out of drive systems of linear motors 24A-24D, a feeder 10 is retreated from an interference range in which a press is interfered with the feeder 10 to a non-interference range by using the one drive system. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an emergency evacuation method for a feeder, and more particularly, to an emergency evacuation method for a feeder that includes a carrier that moves a work between two presses in an advance / return direction and drives the carrier with a plurality of linear motors. Things.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in a so-called tandem press line, a plurality of presses are arranged in a line in a work transfer direction to sequentially process a work. In a so-called tandem press line, a work transfer method between adjacent presses is a robot method or a loader / unloader method. It has been known. Here, the robot system means that a multi-joint type handling robot is installed between adjacent presses, and the handling robot takes out the work from the press in the previous process and carries the work into the press in the next process. It was done. On the other hand, the loader / unloader method has a structure in which a loader and an unloader having a link structure are respectively provided on the upstream side surface and the downstream side surface of the press body, and a shuttle truck is provided between the upstream unloader and the downstream loader. The unloader and the loader carry out the work to and from the press body, respectively, and carry the work to the next process by the shuttle truck.
[0003]
However, in these conventional methods, it is necessary to convey the work by following the intermittent movement of each of the presses on the upstream side and the downstream side, and to prevent interference with a mold or the like at the time of conveying the work. Therefore, there is a problem that the handling speed of the workpiece cannot be increased, and the improvement of the production speed is limited. Further, in the case of the robot type, there is a problem that teaching the transport trajectory is difficult and it takes a long time.In the case of the loader / unloader type, there is a problem that the shuttle truck is placed between the adjacent presses. Since it is necessary to install the apparatus, there is a problem that the apparatus becomes large and a large installation space is required.
[0004]
In order to solve these problems, the present applicant has invented a work transfer method and a transfer device of a tandem press line capable of easily teaching a work transfer locus in a short time and increasing the work transfer speed. (Japanese Patent Application No. 2001-400849). The work transfer device of the invention of the prior application provides a lift beam that can move up and down in parallel with the work transfer direction, and a carrier and a subcarrier that can move along the longitudinal direction of the lift beam. And a cross bar having a work holding means.
[0005]
By the way, in a tandem press line as proposed in the above-mentioned prior invention, the work transfer device (feeder) is operated in synchronization with the movement of the press slide, and the work holding means and the like of the feeder and the press die are connected. The feeder is configured to move in a predetermined motion trajectory so as not to interfere. If an error occurs in the servo drive system during the operation of the feeder, the servo drive system and the servo motor are separated by hard logic, the DC motor is applied to the servo motor, and the feeder is stopped immediately on the spot. You. Also, the press slide is braked by the abnormality detection of the feeder, and the stop operation is performed independently of the feeder.
[0006]
[Problems to be solved by the invention]
However, as described above, there is no problem if the press slide and the feeder device can be stopped at the same time when an abnormality occurs in the feeder, but in fact, the inertia force of the press slide is larger than the feeder and the coasting distance is longer. Then, the feeder stops first, and the press slide stops later. At this time, depending on the emergency stop position of the feeder, the press slide may interfere with the feeder, and this interference may damage or damage a very expensive press die or feeder. There are points.
[0007]
The present invention has been made in order to solve such a problem. In a feeder that moves a work in an advance / return direction between two presses by using a linear motor, an abnormality in a drive system of the feeder is generated. It is an object of the present invention to provide an emergency evacuation method for a feeder that can reliably prevent a feeder from interfering with a press at times.
[0008]
[Means for Solving the Problems and Functions / Effects]
In order to achieve the above object, an emergency evacuation method for a feeder according to the present invention includes
An emergency evacuation method of a feeder comprising a carrier for moving a work in an advance / return direction between two presses, wherein the carrier is driven by a plurality of linear motors.
When at least one of the drive systems of the linear motor is left and an abnormality occurs in another drive system, the press and feeder interfere with each other using the one drive system. The feeder is retracted to an area.
[0009]
According to the present invention, when an abnormality occurs in at least one of the drive systems including a plurality of linear motors that drive a carrier for moving a work in the advance / return direction, the other drive system remains. Then, the feeder is evacuated from the interference area where the press and the feeder interfere with each other to the non-interference area by emergency evacuation by the remaining normal drive system. Therefore, even when the press slide is descending at the time of failure of the drive system, it is possible to reliably prevent the press die and the feeder from interfering with each other, and to prevent the press die or the feeder from being damaged. be able to.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, a specific embodiment of the emergency evacuation method for a feeder according to the present invention will be described with reference to the drawings.
[0011]
FIG. 1 is a front view of a tandem press line according to an embodiment of the present invention, and FIG. 2 is a side view thereof. FIG. 3 is a front view of a work transfer device used in the tandem press line, and FIG. 4 is a sectional view taken along line AA of FIG.
[0012]
The tandem press line 1 of the present embodiment includes a plurality (four in the present embodiment) of presses 2 arranged in series from the upstream side (left side in the figure) to the downstream side at a predetermined interval from each other. 3, 4, 5; a material carry-in device 6 arranged upstream of the most upstream press 2; a product carry-out device 7 arranged downstream of the most downstream press 5; The work transfer device 9 for transferring the upper work 8 (see FIGS. 3 and 4) to the processing station of the first press 2 and the work 8 between the processing stations of the presses 2, 3, 4, and 5 adjacent to each other. And a work transfer device 13 for transferring the work 8 from the processing station of the fourth press 5 onto the product unloading device 7. ing. In the following description, the “work transfer device” is referred to as a “feeder”.
[0013]
Each of the presses 2, 3, 4, and 5 includes an upright 14 as a main body frame, an upper frame 15 disposed above the upright 14 and having a built-in driving force transmission mechanism, and an upright 14 capable of moving up and down on the upright 14. An upper mold that includes a slide 16 supported and moved up and down via the driving force transmission mechanism, and a bolster 18 provided on a bed 17 to be opposed to the slide 16 and mounted on a lower end of the slide 16 The work 8 is configured to be processed by a lower die mounted on the upper end of the bolster 18.
[0014]
Next, the detailed structure of the feeders 9 to 13 will be described. Since the basic configuration of each of the feeders 9 to 13 is substantially the same, the configuration of the feeder 10 arranged between the presses 2 and 3 will be mainly described below as a representative example.
[0015]
As shown in FIGS. 2 and 4, the feeder 10 includes a pair of lift beams 19, 19 that are arranged on the left and right sides in the work transfer direction so as to be separated from each other. A rod 20 extending upward along the upright 14 is attached to an upper portion of the lift beam 19. On the other hand, a lift shaft servomotor 22 is mounted on the upper part of the upright 14 via a support member 21, and a pinion attached to an output shaft of the servomotor 22 meshes with a rack engraved on the rod 20, The lift beam 19 is moved up and down by the forward and reverse rotation of the servo motor 22. Here, the lift axis servomotor 22 is controlled based on a feeder motion set in advance by a control signal from a controller 31 described later.
[0016]
Each of the left and right lift beams 19 is provided with a carrier (main carrier) 23 having a substantially U-shaped cross section so as to hold the lift beam 19 from below, and the carrier 23 extends along the longitudinal direction of the lift beam 19. Be able to move. As shown in FIG. 4, a pair of moving means for moving the carrier 23 along the lift beam 19 is provided between both outer surfaces of the lift beam 19 and the inner surface of the carrier 23 opposed thereto. Linear motors 24 (24A, 24B; 24C, 24D) are provided. Further, linear guides 25 are arranged between the upper outer side surfaces of the lift beam 19 and the inner side surface of the carrier 23 opposed thereto and between the lower surface of the lift beam 19 and the bottom surface of the carrier 23 opposed thereto. The moving operation of the carrier 23 with respect to the lift beam 19 is guided by these three-point supporting linear guides 25. Here, the linear motor 24 includes a magnet 24a disposed on both sides of the lift beam 19 along the transport direction (longitudinal direction), and a transport direction (longitudinal direction) on the inner surface of the carrier 23 facing the magnet 24a. And an armature (carrier 23) having the coil 24b is moved linearly by a change in a magnetic field created on a stator (lift beam 19) having a magnet 24a. Have been.
[0017]
Further, a base plate 23a of a required length is provided below the carrier 23 so as to extend in the work transfer direction, and the subcarrier 26 can move along the base plate 23a. The moving means of the subcarrier 26 is a linear motor 27 comprising a magnet 27a disposed on the lower surface of the base plate 23a along the transport direction and a coil 27b disposed on the upper surface of the subcarrier 26 facing the magnet 27a. (27A, 27B). Further, linear guides 28 are arranged between the lower surfaces on both sides of the base plate 23a and the upper surface of the subcarrier 26 opposed thereto, and the linear guide 28 guides the movement of the subcarrier 26 with respect to the carrier 23. It is configured. A pair of subcarriers 26 facing each other are connected by a crossbar 29, and a plurality of vacuum cups 30 are mounted on the lower surface of the crossbar 29, and the work 8 is sucked by the vacuum cups 30. It has become. Here, the linear motors 24 and 27 are controlled based on a feeder motion set in advance by a control signal from a controller 31 which will be described later, whereby the moving operation of the carrier 23 with respect to the lift beam 19 in the transport direction and the carrier 23 Is controlled along the transport direction of the subcarrier 26 with respect to.
[0018]
In the feeder 10 configured as above, the lift beam 19 is moved up and down by driving the lift axis servomotor 22, and the vacuum cup 30 is moved up and down via the carrier 23, the subcarrier 26 and the cross bar 29. be able to. Further, by driving the carrier 23 along the longitudinal direction of the lift beam 19 by driving the linear motor 24 and offsetting the subcarrier 26 in the moving direction of the carrier 23 by driving the linear motor 27, the crossbar 29 and the vacuum cup 30 can be moved in the work transfer direction. By controlling two orthogonal drive shaft positions in the vertical direction and / or the transport direction in this way, the movement trajectory of the vacuum cup 30, in other words, the transport trajectory of the work 8 can be controlled.
[0019]
The lift-down operation and the transport (advance-return) operation of each feeder are set in advance in the controller 31 (see FIG. 6) in order to avoid interference between the workpiece 8 conveyed by the feeder and a die or the like. The lift axis servomotor 22 and the linear motors 24 and 27 are controlled based on the stroke and timing to be performed, that is, the feeder motion. In the present embodiment, the feeder motion is a two-dimensional motion in a feed axis direction (transport direction) and a lift axis direction (vertical direction), and a press angle set for each axis (feed axis and lift axis). Is determined based on the axis position command value for As shown in FIG. 5, according to the feeder motion of the present embodiment, the work 8 is sucked from the lower die of the processing station of the press 2 on the upstream side at the suction point P and lifted (L) in the axial direction. After being lifted, the workpiece is conveyed in the feed (F) axial direction to the lower die of the processing station of the downstream press 3, and is lowered in the lift axial direction to enter the lower die, and the work is released at the release point Q. Is released. Next, the feeder 10 is once lifted upward and moved in the return direction to return to the processing station of the upstream press 2, and then moved up and down again through the standby point R at the slightly lowered position to be sucked. Returning to the point P, one cycle ends.
[0020]
Next, the servo control system of the feeder 10 in the present embodiment will be described focusing on the operation of loading and retreating the work 8 to the press 3 on the downstream side. The work unloading operation from the upstream press 2 is performed in the same manner.
[0021]
As shown in FIG. 6, the press angle (crank angle) of the press 3 is detected by an encoder (press angle detector) 32 attached to the press 3, and the detected value is input to the controller 31. In the controller 31, when the press angle detected by the encoder 32 is within a predetermined press angle range related to unloading / loading of a work, the linear motors 24A to 33A, 33b,. Control signals are output to 24D, 27A, 27B and the lift axis servomotor 22. The linear motors 24 and 27 and the lift axis servomotor 22 are provided with a speed sensor for detecting the speed of the motor and a position sensor (not shown) for detecting the current position of the motor. When the speed signal detected by the sensor and the position signal detected by the position sensor are input to the controller 31, the speed feedback and the position feedback are applied to each of the servo drivers 33a, 33b,.
[0022]
Thus, the feeder 10 moves up and down the lift beam 19 and moves the carrier 23 and the subcarrier 26 in the feed direction so as to synchronize (follow) the movement of the press 3 when the work 8 is carried into the press 3. Then, after the vacuum cup 30 is moved into the lower mold of the processing station and the work 8 is carried in, an operation of retreating from the lower mold is executed.
[0023]
When the servo drivers 33a, 33b,..., The controller 31 and the like are operating normally, as shown in FIG. Each pair of linear motors 24A, 24B; 24C, 24D is moved along the transport direction by driving.
[0024]
In this normal state, for example, if an abnormality occurs in one of the linear motors 24A (or 24B) or the servo driver 33a (or 33b) of the pair of linear motors 24A and 24B on the left side in FIG. A stop command is issued to the press 3 in accordance with the control signal from the controller 3. At this time, even if the feeder 10 is located in the interference area (dangerous area) where the feeder 10 interferes with the slide 16 of the press 3, the other normal linear motor 24B (or 24A) or its normal servo driver 33b (or 33a) is used to carry the carrier 23. One end side can be driven, and it is possible to retreat from the interference area to the non-interference area. Here, since the driving force on the side where the abnormality has occurred is reduced by half, a slight twisting force acts on the crossbar 29, but there is no hindrance to the movement of retreating from the interference area. After retreating from the interference area, the feeder 10 is stopped following the stop operation of the press 3.
[0025]
As described above, according to the present embodiment, since a pair of drive systems for the linear motor that drives the carrier 23 are provided on each of the left and right sides, when an abnormality occurs in one of the drive systems, ., The linear motors 24A, 24B,..., In other words, by one-lung running, the feeder 10 can be reliably retracted from the interference area to the non-interference area and stopped at a predetermined position. Therefore, it is possible to reliably prevent the press die and the feeder from interfering with each other even when the press slide is descending during an emergency stop, and to prevent the press die or the feeder from being damaged beforehand. it can.
[0026]
In the present embodiment, the structure adopting the structure as shown in FIG. 4 as the arrangement structure of the linear motor 24 and the linear guide 25 in the carrier 23 and the lift beam 19 has been described. On the other hand, various other structures can be adopted as long as the structure includes a pair of linear motors 24.
[0027]
FIG. 7 shows a modification of the carrier structure of the present embodiment shown in FIG. In FIG. 7, portions corresponding to the present embodiment are denoted by the same reference numerals as in FIG. 4 or corresponding reference numerals with dashes ('). In the example shown in FIG. 7A, the linear motors 24 are arranged on both outer surfaces and the lower surface of the lift beam 19, and the linear guides 25 are arranged on both outer surfaces of the lift beam 19. Further, in the example shown in FIG. 7B, in the configuration shown in FIG. 7A, the linear motor 24 on the lower surface of the lift beam 19 is omitted. Further, in the example shown in FIG. 7C, a linear guide 25 is provided on the lower surface of the lift beam 19 in addition to the configuration of FIG. In the example shown in FIG. 7D, a pair of linear motors 24 are arranged on one outer surface of the lift beam 19, and a linear guide 25 is arranged on the other outer surface and the lower surface of the lift beam 19. Have been. In the example shown in FIG. 7E, the carrier 23 has an L-shaped cross section, a pair of linear motors 24 are disposed on one outer surface of the lift beam 19, and the linear guide 25 is It is arranged on the outer surface and the lower surface. Further, in the example shown in FIG. 7F, the carrier 23 has an L-shaped cross section, a pair of linear motors 24 are arranged on one outer surface and a lower surface of the lift beam 19, and the linear guide 25 is lifted. The beam 19 is arranged on its outer and lower surfaces.
[0028]
In any of these configurations, the carriers 23 and 23 'are driven by the pair of linear motors 24, so that the same operational effects as those of the present embodiment can be obtained.
[0029]
FIG. 8 is a cross-sectional view illustrating a carrier structure according to another embodiment.
[0030]
In this embodiment, a bracket 41 having a substantially T-shaped cross section is attached to the lower surface of the central portion of the lift beam 40, and a carrier 42 is arranged so as to hold the bracket 41 from below. A magnet 43a is arranged along the longitudinal direction, and a coil 43b is arranged along the longitudinal direction on the inner surface of the carrier 42 facing the magnet 43a. The magnets 43a and the coil 43b constitute linear motors 43A and 43B. . Guide frames 44 and 45 are attached to the lower surfaces of both sides of the lift beam 40, and a pair of linear guides 46 are provided between the bottom surfaces of the guide frames 44 and 45 and the lower upper surface of the carrier 42 opposed thereto. ing. With such a configuration, the same operation and effect as the above embodiment can be obtained.
[0031]
In each of the embodiments described above, an example in which the present invention is applied to a tandem press line has been described. However, the present invention can be applied to other various systems. Further, the present invention can also be applied to a feeder between press units adjacent to each other in a press including a plurality of press units.
[Brief description of the drawings]
FIG. 1 is a front view of a tandem press line according to an embodiment of the present invention.
FIG. 2 is a side view of FIG. 1;
FIG. 3 is a front view of a work transfer device used in a tandem press line.
FIG. 4 is a sectional view taken along line AA of FIG. 3;
FIG. 5 is an explanatory diagram of a feeder motion according to the embodiment.
FIG. 6 is a block diagram of a servo control system.
FIGS. 7A to 7F are cross-sectional views showing modified examples of the carrier structure of the present embodiment.
FIG. 8 is a cross-sectional view illustrating a carrier structure according to another embodiment.
[Explanation of symbols]
1 Tandem press line 2,3,4,5 Press 8 Work 9,10,11,12,13 Work transfer device (feeder)
16 Slide 18 Bolster 19, 40 Lift beam 22 Lift axis servo motor 23, 42 Carriers 24A to D, 27A, 27B, 43A, 43B Linear motor 26 Subcarrier 29 Crossbar 31 Controller 32 Encoder (press angle detecting means)

Claims (1)

An emergency evacuation method of a feeder comprising a carrier for moving a work in an advance / return direction between two presses, wherein the carrier is driven by a plurality of linear motors.
When at least one of the drive systems of the linear motor is left and an abnormality occurs in another drive system, the press and feeder interfere with each other using the one drive system. An emergency evacuation method for a feeder, comprising retreating the feeder to an area.

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